MikeyBrah

I'm new to this forum so I do apologize for being a noob.

So about two months ago, car was idling rough and was limping. Figured I'd clean out both MAF sensors and that would do the trick. After the cleaning, the car drove fine for another week. Then it went into full limp mode, car was idling rough and wouldnt rev past 1k rpms. I had it towed to a small shop overnight and when they got it, the car was driving fine so I got the battery replaced because I needed a new battery anyway so why not. The car went into limp mode again the next day and I took it to Nissan Dealership this time and they claimed it was an alternator, so they replaced the alternator and did an idle relearn.

Car still continues to go into limp mode, while throwing no codes except for the codes I already have which are for the 02 sensors in the Cats which I have test pipes so I'd expect that. Let Nissan hold onto to the car for 2 weeks as they tried to see what was the problem. Car went into limp mode once under their care. They couldn't find the exact problem so they gave it back to me and it went back into limp mode on my commute home from work. Turned it off for ten minutes and it ran fine after that but it keeps continuing to go into limp mode.

It typically goes into limp mode when the weather is bad, slippery roads, light snow on the ground. I know it could be the throttle body but i'm not sure how to test if there is a fault in the wiring system or if its just a bad throttle body or maybe cleaning?. Since the HR has two throttle bodies, I don't want to dump money into buying parts not knowing what the exact problem is.

Any body know what might be the issue or how to fix this?
I appreciate all responses

07 Nissan 350z HR
Mod list:
245/40/18 Front
295/40/18 Rear
Berk Test pipes
Megan Racing Y-Pipe
Nismo Exhaust
Z1 Motorsports lightweight Clutch and flywheel

John_B

iTrader: (1)

Try cleaning the TB's. Unplug TB wire and battery first**.
Lift the flap and make sure there is no oil build up that could possibly make it stick. If there is use a TB or brake cleaner.

John_B

iTrader: (1)

......

RobPhoboS

Dont lift the flap.

MikeyBrah

Thanks, I will definitely try that on my next day off and see if that helps.

dboyzalter

iTrader: (3)

How many miles? The throttle body seems like an unlikely problem. Your tire size is way off... Hopefully you have a base model Z otherwise I would guess that massive stagger could be part of the problem.

If Nissan cant figure it out its highly unlikely that we will be able to pin point the problem...

However those rear tires are way tall so thats my guess.

Don't mess with your throttle body, moving the flaps by hand can mess up the electronics causing you to need new throttle bodys when they are perfectly fine.

Welcome to the forum.

MikeyBrah

90,000 miles, and it is a base model.
I thought I'd ask on here anyway to see if anyone had different suggestions.

I got these wheels in May and drove the whole summer and fall with them with no problems. The tire sidewall does rub a bit when I hit a major pothole but I had no problems for 6 months so if it was the tires why now? I'll switch to the factory OEM wheels to see if it really makes a difference.

John_B

iTrader: (1)

I highly doubt the tires size will cause the rough idle.

I've cleaned my TB's several times before switching to a 70mm Big Bore TB's
My issue in the past was having oil buildup around the flap and it would get stuck.

Like I noted above: Disconnect the battery first then disconnect the TB harness before cleaning.

dboyzalter

iTrader: (3)

If its a base model then the tire size shouldn't be the issue. Unless because the rear is so much taller than the front its throwing off the ABS because the speeds from the front to the back are so different.

Not saying it cant be a throttle but I think the dealership would have figured that out when they had it for 2 weeks...

My next guess ummmm

RobPhoboS

I'm going through similar-ISH problems, not exactly the same.
What codes are being thrown up ? (if you don't know get yourself a bluetooth/wifi reader and appropriate app to read the codes)
Have you pulled out the spark plugs to see what they are looking like ?

It could be sensors like the crank/cam/knock+harness, coil packs and so on.

You can get yourself a multimeter and test those things out methodically first.

And I'll say it again, do NOT touch the flap inside the TB, spray some carb cleaner sure to get rid of any oil.

The other thing it could be is just dirty connectors, so a can of contact cleaner and some patience going around cleaning them out too.

travlee

iTrader: (8)

dont touch the butterfly.......

dboyzalter

iTrader: (3)

Do not double click the mouse.

John_B

iTrader: (1)

I would just remove the whole TB if you are super sensitive like all the peeps here lol.
There is a small lip around the flap that brake cleaner won't be able to penetrate.

90k miles without a PCV delete, I can only imagine how much oil build-up has accumulated around the lower manifold and TB.

While that manifold is up, check the coil packs and spark plugs.

Mycal_z33

Any luck with the problem. I'm having similar issues except mine isn't idling funny. My 350 goes into limp if the rpms go over 5.5k. I'm thinking it could be something to do with the differential. i was getting a clunk from the rear of the car while shifting at high rpms before the limp mode problem started happening

travlee

iTrader: (8)

he hasnt logged in for over a year... check for a vacuum leak, and then check the rear subframe bushing

Mycal_z33

okay..thanks for the reply

lealjose1993

I am getting the same issue on my 07 350Z, I have cleaned the TB's and the MAF sensors. My car idles fine and has no CEL but when I accelerate it stays between 2-3k rpms, when I cleaned out my TB that problem went away and I felt the hp that I was missing. Two days later went right back to where I started. I haven't changed the the spark plugs yet, also battery is new and alternator is good.

Mods:
Tomei cat back exhaust
Takeda dual Intake

mikep350z

I have changed the throttle body and sensors. The code it is showing now is the throttle motor relay. I have seen hundreds of forums and they all end with "thanks I'll try that and see if that works update after I try this" but I've yet to see am answer to this problem??!!! So since I've replaced the tb and sensors do I need to do the "pedal dance" to get it out of limp mode for the idle relearn or what??? I have searched and searched and all I have come up with is that the nissan tech's are retarded at the dealership and so far have read they haven't been able to fix a car that they manufactured... This is the only vehicle I have and I've got 3 weeks to get out of this house because I have sold it and um I'm freakin stuck because my car is in limp mode and will not go past 2k rpm. HELP?! SOS?!!!